1. Field of the Invention
The invention pertains to the transmission and reception of base band or sub-nanosecond electromagnetic signals relative to reflecting moving objects and more particularly relates to the use of such object-reflected signals for the measurement of the speed of moving objects.
2. Description of the Prior Art
In past systems for measuring the speed of a craft, it has been common practice to rely upon the Doppler shift of a reflected continuous wave carrier signal or upon other radio measures of the rate of change of the distance to the reflecting target, such as those involving use of automatic range tracking means in pulsed carrier systems. Such approaches are generally complex and costly, since they require the transmission of relatively high power levels of carrier energy. Such conventional methods also generally require the sensor system to direct high frequency radiation along the path of travel of the moving object or craft. Such a requirement dictates placement of the sensor within or at the end of the path of the craft, which is clearly dangerous, or which requires inconvenient compensation of the apparatus read-out for an angular off-set of the sensor from the path.